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Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust

Latest news

Recent projects

  • Latest news

    25 Mar 2026

    BRE 365 Soakaway Testing

    Simon Ruddlesden was pleased to present at the AGS Annual Conference, to talk about BRE 365 soakaway testing, asking the question, though not necessarily providing the answer: Should we be carrying out BRE 365 soakaway testing in geologies where previous testing has shown soakaway/ infiltration drainage to be unsuitable? The BRE 365 soakaway test is widely accepted and requested as the field test that is to be carried out to assess the suitability of the ground for soakaway/ infiltration drainage. However, the test is not without danger, mainly due to working at height risks, and it is relatively wasteful of resources, including fuel and water. If previous testing results consistently and convincingly show that certain geologies are unsuitable for soakaway/ infiltration drainage, should a relatively unsafe and not particularly sustainable test be carried out? Using data from over 5,000 tests on more than 1,200 sites investigated by Ruddlesden geotechnical over the last 20 years, mainly in the South West, there is a clear and understandable correlation between unsuccessful tests and the underlying geology, where the underlying geology comprises predominantly lower permeability mudstones and clays, notably the Mercia Mudstone Group, Lias Group and Oxford Clay Formation, although there are a number of anomalies, which can usually be explained by a closer inspection of the local geology, including superficial deposits. More data and research will be required if regulators and designers are to accept that no testing is required in certain geologies. The presentation sparked an interesting discussion afterwards, and it is hoped that it will have inspired others to share their data and/ or offer technical support, to ultimately produce a map that provides confidence to regulators and designers that BRE 365 testing is not required in certain geologies. Please contact us directly if you would like to discuss this further.

    BRE 365 Soakaway Testing
    BRE 365 Soakaway Testing

  • Recent projects

    Ground Gas Assessment for Large Residential Development Site

    After completing a Phase 1 contamination assessment, Ruddlesden were instructed to undertake a ground gas risk assessment for a proposed residential development near Rugby. The southern and western boundaries of the site were bordered by an active landfill site and historical landfilling activities had taken place within the southwest of the site. Twelve ground gas monitoring wells were installed to varying depths within the confines of the proposed residential development site. The wells were monitored on twelve occasions following installation with a landfill gas analyser, for oxygen, methane, carbon dioxide and gas flow. Atmospheric pressure and other environmental conditions were also recorded. The results of the monitoring were used to produce a gas screening value (GSV), which was used in the assessment to ascertain whether any protective measures were required for new dwellings. The results indicated that a suitably installed gas proof membrane and subfloor ventilation would provide sufficient protection against the levels of ground gas present.

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  • Recent projects

    Contamination Remediation Strategy Outlines Requirements for Residential Development

    In order to satisfy a planning and NHBC land quality conditions, Ruddlesden produced a contamination remediation method statement, which summarised the contamination risks across the site and set out a clear and structured approach for remediating the site for the developer, to satisfy regulators and warranty providers. Ruddlesden geotechnical had previously undertaken a Phase 1 and Phase 2 contamination investigation and assessment, which had indicated that the site was covered by surficial thicknesses of made ground containing loose fibres of chrysotile asbestos. Additionally, several underground fuel storage tanks and a historical air raid shelter, filled with asbestos containing materials (ACMs). The remediation strategy included excavation and removal of the underground fuel storage tanks and ACM, to be undertaken by licensed contractors, together with capping of garden areas with 600mm of clean soil underlain by a geotextile membrane. The remediation strategy also outlined the validation testing requirements, which were subsequently undertaken by Ruddlesden geotechnical.

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